Sulfoxide detergent



3,271,318 SULFOXIDE DETERGENT Jim 5. Berry, Springfield Township, Hamilton County, and Warren ll. Lyness, Mount Healthy, Ohio, assignors to The Procter & Gamble Company, Cincinnati, Ohio, a corporation of ()hio No Drawing. Uriginal application Nov. 14, 1962, Ser. No. 237,715. Divided and this application July 28, 1965, Ser. No. 482,978

3 Claims. (Cl. 252-438) This application is a division under Rule 147 of copending patent application filed November 14, 1962, Serial No. 237,715.

This invention relates to novel 1,1-bis-sulfoxides and detergent compositions containing them. 7

In constant improvement of organic detergent compounds certain features have been found to be highly desirable. These features include resistance toward the ingredients imparting hardness to water and a high degree of detergency. Although there are a number of organic detergent compounds which have these characteristics, detergent compounds having additional desirable characteristics find a wider scope of application.

US. Patent 2,658,038, Wayne A. Proel-l, describes a class of 1,2-bis-sulfoxide detergent compounds which are relatively mild to the skin and which have effective detergency characteristics. These 1,2-bis-sulfoxides have the formula Where R is a lower alkyl, R is an alkyl containing 6 to 20 carbon atoms and R is H or lower alkyl. Attempts to formulate these 1,2-bis-sulfoxide compounds into detergent compositions containing alkaline builder materials (for the purpose of enhancing the detergency of the 1,2-bis-sulfoxide detergent compounds) showed that the LQ-bis-sulfoxides are subject to decomposition in the presence of such alkaline materials. Apparently, the presence of an alkaline material catalyzes the decomposition of a 1,2-bis-sulfoxide into odoriferous products (e.g., methyl disulfide), thereby reducing the effective amount of detergent and creating a severe odor problem. This decomposition problem indicated that bis-sulfoxi-des would generally be unsuitable for alkaline built detergent compositions.

It is an object of this invention to provide novel bissulfoxide detergent compounds having a high degree of detergency and stability in an alkaline environment. It is a further object of this invention to provide alkaline built detergent compositions containing such bis-sulfoxide compounds.

It was found that these and other objects are achieved in a novel class of 1,1-bis-sulfoxides having the structure set forth below and in alkaline detergent compositions containing such compounds, which have a surprising alkaline stability, as hereinafter more fully described.

wherein R is an alkyl group containing from about 8 to about 16 carbon atoms, preferably in a straight chain, and R and R are alkyl groups containing from 1 to 2 carbon atoms. Preferably R and R are methyl. The class of compounds described will hereinafter be referred to more simply as 1,1-bis-sulfoxides. Examples of the compounds of this invention are:

3,271,3l8 Patented Sept. 6, 1966 1,1-bis(methylsulfinyl) nonane 1,1-bis(methylsulfinyl) decane 1,1-bis(methylsulfinyl) undecane 1,1-bis (methylsulfinyl) dodecane 1,1-bis(methylsulfinyl) tetradecane 1,1-bis(methylsulfinyl) pentadecane 1,1-bis(methylsulfinyl) hexadecane l,l-bis(methylsulfinyl) heptadccane 1 ,-1-bis (ethylsulfinyl) tridecane An alternative synthesis route can be followed:

(1) The preparation of 1,1-bis(alkylmercapto) methane by reacting an alkali metal lower alkyl mercaptide with dihalomethane, e.g., dichloromethane;

(2) The alkylation of the 1,1-bis(alkylmercapto) methane, with a higher alkyl halide for example, in the presence of a strong base, such as sodami-de, to form 1,1-bis- (alkylmercapto) alkane;

(3) Oxidation of the 1,1-bis(alkylmercapto) alkane, with H 0 for example, to form 1,1-bis(alkylsulfinyl) alkane (i.e., 1,1-bis-sulfoxide).

These steps are illustrated by the following exemplary equations wherein R is a C C alkyl group:

CH Cl 2NaSCH CH (SCH 2NaCl In 1,1-bis-sulfoxides of this invention, R in the above general formula can be derived from naturally occurring fats and oils or from synthetic sources. Mixtures of 1,1- bis-sulfoxides are very suitable wherein the R groups vary in chain length in the C to C range, as for example, the alkyl groups from coconut fatty alcohol or distilled coconut fatty alcohol.

The 1,1-bis-sulfoxides of this invention are useful per se as detergent and surface active compounds. The uses to which surface active compounds can be put are numerous and well known, e.g., preparing oil-in-water emulsions, textile treatment, dyeing, flotation, preparation of rubber latex, and the like. Desirably the 1,1-bissulfoxides are used with alkaline builder materials to form built detergent compositions, as for example, liquid, bar, flake, granular or tabletted granular compositions. Such compositions have enhanced detergency characteristics due to the coaction in aqueous washing solution between the 1,1-bis-sulfoxides and the alkaline builder material. It is in such an alkaline medium that the surprising and advantageous usefulness of the l,i1-bis-sulfoxides, i.e., superior stability in the presence of alkaline materials, is best demonstrated. Preferably the alkaline builder in such detergent compositions is a material selected from the class consisting of water soluble in- 3. organic alkaline builder salts, water soluble organic alkaline sequestering builder salts and mixtures thereof. Desirably the ratio of 1,1-bis-sulfoxide to the alkaline builder material is in the range of about 4:1 to about 1:20. (Parts, ratios and percentages herein are by weight.) Preferably the alkaline builder material should provide a pH of about 8 to about 11 when the detergent composition is dissolved in water.

Water-soluble inorganic alkaline builder salts used alone or in admixture are alkali metal carbonates, borates, phosphates, polyphosphates, bicarbonates and silicates. (Ammonium or substituted ammonium builder salts, e.g., triethanolamine, can also be used.) Specific examples of such salts are sodium tripolyphosphate, sodium carbonate, potassium carbonate, sodium tetraborate, sodium pyrophosphate, potassium pyrophospha-te, sodium bicarbonate, potassium tripolyphosphate, sodium hexametaphosphate, sodium sesquicarbonate, sodium monoand diortho phosphate and potassium bicarbonate. Such inorganic builder salts enhance the detergency of the subject 1,1-bis-sulfoxides.

Examples of organic alkaline sequestrant builder salts used alone or in admixture to enhance detergency are alkali metal, ammonium or substituted ammonium, aminopolycarboxylates, e.g., sodium and potassium ethylenediaminetetraacetate, sodium and potassium N-(Z-hydroxyethyl)-ethylenediaminetriacetates, sodium and potassium nitrilotriacetates and sodium, potassium and triethanolammonium N-(Z-hydroxyethyl)-nitrilodiacetates. Mixed salts of these polycarboxylates are also suitable. The alkali metal salts of phytic acid, e.g., sodium phytate are also suitable as organic alkaline sequestrant builder salts (see US. Patent 2,739,942). Also suitable are the water soluble salts of ethane-l-hydr-oxy-l,l-diphosphonate, e.g., the trisodium and tripotassium salts.

The detergent compositions of this invention can contain any of the usual adjuvants, diluents and additives, for example, anionic, nonionic, ampholytic, cationic or zwitterionic detergents, perfumes, anti-tarnishing agents, anti-redeposition agents, bacteriostatic agents, dyes, fluorescers, suds builders, suds depressors, and the like without detracting from the advantageous properties of the composition. Examples of anionic detergents are sodiumcoconut soap, sodium dodecylbenzene sulfonate and potassium tallow alkyl sulfate. Examples of nonionic detergents are dodecyldimethylamine oxide and the condensation product of coconut fatty alcohol with 5.5 moles of ethylene oxide. An example of a zwitterionic detergent is 3-(N,N-dimethyl N hexadecylammonio)-2-hydroxypropane-l-sulfonate. An example of an ampholytic detergent is sodium-3-dodecylaminopropionate. An example f-o an alkaline-compatible cationic detergent is dodecylmethylbenzyl sulfoxonium methosulfate.

Following are examples which illustrate the 1,1-bissulfoxide compounds and compositions of this invention. There are, of course, modifications of these illustrations which can be made by those skilled in the art without departing from the scope of this invention as defined in the appended claims.

EXAMPLE I Preparation of 1,1-bis(methylmercapt) dodecane Lauraldehyde (11 3 g., 0.62 mole) was dissolved in 500 ml. of benzene and the solution cooled to 0 C. The mixture was saturated with anhydrous hydrogen chloride at 0 and methyl mercaptan 108 g. (2.24 mo1es- 80% excess) was bubbled in at 0 C. with stirring of the reaction mixture. Stirring was continued 2 hours at 0 C. following completion of the addition of methyl mercaptan, and the mixture was allowed to stand overnight at 0 C. Separation of an aqueous layer occurred during the addition and subsequent standing. The mixture was washed with 50 ml. of water neutralized with sodium bicarbonate solution followed by a water washing. The organic material was dissolved in ether, washed twice with water, and the ether solution dried over magnesium sulfate. Following evaporation of the ether solvent the residual material was fractionally distilled to yield 88.7 g. (55% yield) of 1,1-bis(methylmercapto) dodecane.

Preparation of 1,1-bis(methylsulfinyl) dodecane grams of 1,1-bis(methylmercapto) dodecane (0.305 mole) was dissolved in 200 ml. of ethanol, and 69 ml. of 30% hydrogen peroxide (0.67 mole, 10% excess) was added at room temperature with stirring. The mixture was warmed to 45 C. for 1 hour until a monophasic system resulted. Following overnight standing of the reaction mixture, the solution was cooled to -10 C. and filtered. The filter cake was dissolved in refluxing acetone and recrystallized by cooling to 10 C. The 1,1-bis(methylsulfinyl) dodecane obtained by filtration melted at 62.6-65" C. and weighed 23.9 g. Further processing of the mother liquors at lower temperatures afforded recovery of additional 1,1-bis-sulfoxide. For example, an additional 5 g. of material substantially identical to the 23.9 g. crop obtained above was obtained by additional chilling to 40 C. Infrared spectra of these crops show strong sulfoxide bands at 9.5 microns and no sulfone bands at the 7.6 and 8.8 micron positions. Further recrystallization affords concentration of higher melting diastereoisomers (melting points up to C.) without any noticeable change in solution spectra. Analyses on the 1,1-bis-sulfoxide follow: Found: C. 58.3; H, 10.5; 0, 10. 2. Calculated: C, 58.4; H, 11.1; 0, 10.4.

1,1-bis(ethy1sulfinyl) dodecane can be prepared in a manner analogous to the process of Example I by using a molar equivalent amount of ethy-lmercaptan instead of methylmercaptan. 1,1-bis(methylsulfinyl) tetradecane can be prepared in a manner analogous to the process of Example I by using a molar equivalent amount of myristaldehyde instead of lauraldehyde.

EXAMPLE II Preparation of 2,4-dithiapentane Methylmercaptan (96.2 g., 2.0 moles) was added to a solution of 80 g. (2.0 moles) of sodium hydroxide dissolved in 200 ml. of water and 300 ml. of ethanol while keeping the temperature at 010 C. Methylene chloride (84.9 g., 1.0 mole) was added to the resulting mercaptide solution at 10-15 C. The mixture was warmed to room temperature and an additional 25 g. of methylene chloride was added. The well-stirred mixture was heated to 60-70 for 1 hour. The lower layer was then separated and the upper aqueous layer extracted twice with petroleum ether. The petroleum ether extract was combined with the lower organic layer and washed twice with water and dried over magnesium sulfate. After evaporation of petroleum ether the yellow-orange organic residue was distilled through a helices-packed column. Fractions boiling up to 146 were obtained and discarded. The product boiled at l46.5149, yield was 28.8 g. (27%). The product had a very strong mustard-cabbage odor.

Alkylation of 2,4-dithiapentane To a solution of sodamide in 150 ml. of liquid ammonia, prepared in the conventional manner from 6.2 g. (0.27 g. atom) of sodium metal catalyzed by 0.25 g. powdered ferric nitrate, was added 2,4-dithiapentane (28.8 g., 0.266 mole). The dithiapentane was added to the sodamide solution at the reflux temperature of ammonia and was stirred at the ammonia reflux temperature 1 /2 hours. At the end of this period dodecyl bromide (66.2 g., 0.266 mole) was added dropwise to the stirred mixture. After addition was complete the ammonia was allowed to evaporate off, and ethyl ether was added as necessary to maintain the mixture-liquid stirrable. After allowing the mixture to stand overnight, water was added and the organic layer separated. Following washing of the aqueous layer with ether and combining the ether extracts with the ethereal solution, the combined ether extracts were washed twice with an acidic ethanol-water solution. The ethereal extracts were then washed twice with water until neutral and dried over magnesium sulfate. After removal of the ether the product was fractionated through a Vigreaux column and the fraction boiling at 152-154" C. at 0.75 mm. of mercury was collected. The yield of the product, 1,1-bis(methylmercapto) tridecane, was 43.1 g. (58.5%). The product had refractive index n =1.4879, d =0.915. Sulfur analyses gave 22.93% sulfur (theory=23.18).

Oxidation of 1,1-bis(methylmercapt0) tridecane To 16.2 g. (0.059 mole) of 1,1-bis(methylmercapto) tridecane dissolved in 100 ml. of ethanol was added slowly, with stirring at room temperature, 6.0 g. (0.176 mole) of 30% aqueous hydrogen peroxide. The mixture was stirred until homogeneous and allowed to stand for 48 hours. The ethanol was evaporated in vacuo after the addition of platinum catalyst to enhance peroxide decomposition. After the removal of solvents the residue was dissolved in 400 ml. of hexane and filtered hot through a glass filter paper to remove catalyst. The filtrate was cooled slowly to room temperature, whereupon a crystalline fraction of the desired 1,1-bis-sulfoxide separated. This material was harvested by filtration. It melted at 88.5-92 C. and weighed 4.6 g. Analyses gave percent 0:58.29, percent H=10.52; percent 0 =10.17 (theory: percent C=58.40; percent H=11.10; per-cent 0:10.37). Further processing of the mother liquors can be carried out to yield more 1,1-bis-sulfoxide diastereoisomeric mixtures of lower melting point.

Built laundry detergent compositions containing 50% sodium tripolyphosphate, 30% sodium sulfate and 20% 1,1-bis(methylsulfinyl) tridecane, resulted in lipid soil detergency properties (using naturally soiled cloth) superior to like formulations containing sodium dodecyl benzene sulfonate and approaching like formulations containing sodium tallow alkyl sulfate. The same basic formulation, but containing 1,1-bis(methylsulfinyl) undecane or 1,1-.bis(methy1sulfinyl) pentadecane had satisfactory detergent characteristics but not as desirable as those compositions containing the C homolog. As regards detergency, these 1,1-bis-sulfoxides in built compositions were about equal to 1,2-bis-sulfoxides in built compositions (freshly prepared) containing, respectively, the same long chain alkyl groups.

As determined by guinea pig mildness tests, the 1,1- bis-sulfoxides of this invention, e.g., 1,1-bis(methylsulfinyl) tridecane, are very mild to the skin. Such guinea pig tests are described in Canadian Patent 639,398, issued April 3, 1962, to Howard F. Drew et a1.

1,1 bis sulfoxides, e.g., 1,1 bis (rnethylsulfinyl) tridecane, can be used per se as detergents for hand washing or washing of woolens in aqueous solution of 1% concentration for example.

To test the alkaline stability of the 1,1-bis-sulfoxides, of this invention, particularly as compared to 1,2-bissulfoxides, 8% aqueous solutions of potassium pyrophosphate were used. A series of samples containing 3 grams of 1,1-bis(methylsulfinyl) tridecane in 150 ml. of the pyrophosphate solution was compared with a like series of 3 grams of 1,2-bis(methylsulfinyl) tetradecane in 150 ml. of the pyrophosphate solution. (The difference in one methylene group was found to be not significant for purposes of the comparison.) The solutions were kept at 60 C. and pH 10. A slow stream of nitrogen was used to sweep volatile products into traps containing 3% aqueous mercuric chloride. Periodically the precipitated complex of the methyldisulfide with mercuric chloride which formed in the traps was removed, dried and weighed to assess the rates of formation of decomposition products. In 14 days the 1,1-'bis-sulfoxide produced no precipitate. The l,2-bis-sulfoxide produced 0.6 gram of precipitate in 1 day, 1.0 gram in 5 days and 1.1 grams in 12 days. At this point, decomposition of the 1,2-bissulfoxide was substantially complete. This demonstrated the surprising alkaline stability of the 1,1-bis-sulfoxide as compared to the 1,2-bis-sulfoxide.

The 1,1-bis-sulfoxides of this invention can be used in effective alkaline detergent compositions having the following formulations:

Granular detergent: Percent 1,l-bis(methylsulfinyl tridecane 10 Sodium dodecylbenzene sulfonate (the dodecyl group being derived from tetrapropylene) 10 Sodium tripolyphosphate 50 Sodium sulfate 3O Granular detergent:

1,1-bis(ethylsulfinyl) tridecane 10 Condensation product of one mole of dodecanol and twelve moles of ethylene oxide 3 Sodium pyrophosphate 57 Sodium carbonate 3 Trisodium phosphate 3 Sodium sulfate 24 Liquid detergent:

1,1-bis(methylsulfinyl) undecane 6 Sodium dodecylbenzene sulfonate 6 Potassium pyrophosphate 10 Potassium nitrilotriacetate 10 Potassium toluene sulfonate 8 Sodium silicate 3.8 Carboxymethyl hydroethyl cellulose 0.3 Water Balance Liquid detergent:

1,1-bis(methylsulfinyl) pentadecane 5 Ethanol 1O Tetrasodium ethylenediaminetetraacetate 10 Water What is claimed is:

1. An alkaline detergent composition consisting essentially of a 1,1-bis-sulfoxide compound having the formula:

wherein R is an alkyl group containing from about 8 to about 16 carbon atoms; R and R are alkyl groups containing 1 to 2 carbon atoms and an alkaline builder salt selected from the group consisting of water soluble inorganic builder salts, water soluble organic alkaline sequestrant builder salts and mixtures thereof, the ratio of said sulfoxide compound to said builder salt being in the range of about 4:1 to about 1220/ 2. The composition of claim 1 wherein said sulfoxide compound is 1,1-bis(methylsulfinyl) tridecane.

3. The composition of claim 1 wherein said alkaline builder salt is sodium tripolyphosphate.

References Cited by the Examiner UNITED STATES PATENTS 2,658,038 11/1953 Proell 252-161 2,787,595 4/1957 Webb 252-138 3,124,618 3/1964 Berry 252-138 XR LEON D. ROSDOL, Primary Examiner.

ALBERT T. MEYERS, Assistant Examiner. 

1. AN ALKALINE DETERGENT COMPOSITION CONSISTING ESSENTIALLY OF A 1,1-BIS-SULFOXIDE COMPOUND HAVING THE FORMULA:
 3. THE COMPOSITION OF CLAIM 1 WHEREIN SAID ALKALINE BUILDER SALT IS SODIUM TRIPOLYPHOSPHATE. 